Heretofore, substrate processing systems for the application of process treatments to substrates have been known in the industry. Such a substrate processing system is equipped with a transport robot, a transfer robot and a substrate transfer relay device. The transport robot is configured so as to transport substrates between a hoop and the substrate transfer relay device. On the other hand, the transfer robot is configured so as to transfer substrates between a chamber that carries out a process treatment and the substrate transfer relay device. And, the substrate transfer relay device is configured such that the substrates transported and transferred can be placed thereon, whereby to facilitate the delivery of substrates between the transport robot and the transfer robot.
As an example of the transfer robot of the substrate processing system of the type as described above, there is a substrate transfer robot as set forth in, for example, Patent Literature 1. This substrate transfer robot has two hands each capable of placement and holding of a single substrate. For example, the substrate transfer robot receives, with the aid of one of its two hands, a single substrate placed in the substrate transfer relay device while the other hand is not in use. Thereafter, the substrate transfer robot moves the other hand to a chamber to receive a treated substrate in the chamber, and subsequently places the substrate held in the one hand into the chamber. And, the two hands are brought back again to the substrate transfer relay device, and the treated substrate held in the other hand is retuned to the delivery device while the one hand receives another substrate.
In addition, as another example of the transfer robot of the substrate processing system, there is a substrate processing device as set forth in, for example, Patent Literature 2. This substrate processing device is equipped with a load lock chamber section. The load lock chamber section which includes a buffer unit equivalent to a substrate transfer relay device wherein it is designed such that a substrate transferred from the hoop is placed on the board of the buffer unit. In addition, the board is movable up and down in a vertical direction, thereby enabling a transfer module of the transfer chamber section to receive the substrate placed on the board.